P0106 Code on a Cadillac: MAP Sensor Performance (Cadillac Guide)

P0106 on a Cadillac is "Manifold Absolute Pressure (MAP) Sensor Performance." The MAP reading is in range, but it does not behave the way the engine computer expects. On a modern Cadillac that expectation comes from GM's airflow model, so the code can be set by a vacuum leak, a loose intake manifold or a wiring fault as easily as by a bad sensor. GM's Cadillac documents add two surprises. On the 6.2L Escalade and CTS-V, P0106 together with P0506 is GM's documented sign of a broken valve spring. And several early Cadillac engines — the Catera, the 3.2L CTS and the first 3.6L V6s — have no P0106 at all in GM's own tables.

What Does P0106 Mean on a Cadillac?

The MAP sensor measures absolute pressure inside the intake manifold: low at idle when the throttle is nearly closed, close to atmospheric at wide-open throttle, and above atmospheric under boost on a turbocharged Cadillac. The engine control module (ECM) uses it for load, fuel and spark calculations, and as one input to its model of how much air the engine is breathing.

GM's wording for P0106 is MAP Sensor Performance. GM's 2019 tables describe it as a failure "such as when a MAP value is stuck in range." That separates it from the circuit codes:

How GM Tests the MAP Sensor

The test has changed a lot across Cadillac generations.

Northstar, late 1990s. GM's 1999 parameters for the 4.6L LD8 and L37 (DeVille, Seville, Eldorado) describe P0106 as a rationality check on a noisy signal: the raw MAP reading changing by more than 10 kPa within 12.5 milliseconds while engine speed, throttle and A/C state are steady. It needs 8 failures in 10 tests and is a Type A code — the light can come on the first trip. That is an erratic-signal test, which points at connectors and wiring as much as at the sensor.

Modern engines. GM's 2019 tables use the Intake Flow Rationality Diagnostic (IFRD). The ECM calculates two or more expected MAP values from the MAF, throttle position and rpm, then compares them with the real reading. On naturally aspirated engines such as the 3.6L, P0106 fails when the measured MAP misses both models by more than 22 kPa while the throttle model still agrees. There is also an engine-off check: after the car has sat long enough for pressures to equalize, the MAP reading should match the expected atmospheric pressure range. Most of these entries are Type B, two-trip codes.

One Cadillac exception stands out: in GM's 2019 table section for the 3.0L twin turbo (LGW) in the CT6, P0106 is Type A, one trip.

The practical consequence of the model-based test is that a vacuum leak, a loose intake manifold or a faulty MAF can make a good MAP sensor look wrong.

Which Cadillacs Set P0106

GM's tables list P0106 for the Northstar V8s from 1997 through 2007, the 2003–2006 Escalade 6.0L, the 2011 Escalade and CTS-V V8s, the 2011 3.0L V6, and the 2013-and-later Cadillac engines in the ATS, CTS, XTS, SRX, CT6, XT4, XT5, XT6, CT4, CT5 and Escalade.

The engines that don't use it. GM's tables for the 1997–2000 Catera 3.0L list no MAP sensor codes at all. GM's 2003 and 2004 tables for the 3.2L LA3 in the CTS, its 2004 and 2005 tables for the 3.6L LY7 (CTS, SRX, STS), its 2008 and 2011 tables for the 3.6L LLT, and its 2011 table for the SRX 2.8L turbo list no P0106. If a generic scanner shows P0106 on one of those cars, double-check the code and the engine.

GM documents name P0106 specifically on:

• 2013–2017 ATS (2.0T LTG and 2.5L LCV), 2014–2017 CTS 2.0T and 2016–2017 CT6 2.0T — loose intake manifold bolts (PIP5529B).
• 2015–2019 Escalade 6.2L (L86) and CTS-V 6.2L (LT4) — broken valve spring with P0106 and P0506 (PIP5423 and PIP5423B).
• 2021 Escalade 6.2L (L87) — a broken valve spring PI, a MAP sensor PI and a dealer-inventory service update.
• 2016 Escalade — a pinched harness on the 5-volt reference 3 circuit (PIP5344).

What GM's Bulletins Say

ATS, CTS and CT6: loose intake manifold bolts. PIP5529B covers stall, hesitation and any combination of P0068, P0101, P0106, P0131, P0137, P0171, P0324, P0326, P0331 and P0506. If service information does not lead to a fix, GM says to check the intake manifold bolts for looseness, then remove one bolt at a time, add medium-strength threadlocker and torque them in sequence to the SI specification. GM says not to replace the intake manifold gasket unless testing shows it still leaks after the bolts are torqued.

Escalade and CTS-V 6.2L: P0106 and P0506 means look for a broken valve spring. PIP5423B, for 2015–2019 Escalade (L86) and CTS-V (LT4) models among other GM V8s, says a check engine light with P0106 and P0506 may be caused by a broken valve spring. The procedure is to remove the valve cover and inspect for a broken spring; if one is found, inspect the intake manifold for a collapsed runner. Replace the spring if the valve did not drop and damage the engine. GM does not explain in the PI why this pair of codes results; the takeaway is that on these engines a MAP sensor is not the first part to buy.

2021 Escalade 6.2L: valve springs again. PIP5752M covers 2021 Escalades with the 6.2L L87 built between July 1 and December 16, 2020, with a check engine light, misfire and engine noise and possible P0300, P0106 and P0506 (plus several P318x codes). After a cylinder leakage test on the affected cylinder, GM's instruction for the 6.2L is: below 800 km (500 miles), replace all valve springs; above that, replace only the broken one. Also check the intake runner for that cylinder. If there is cylinder leakage, further inspection is needed to find the extent of the damage.

2021 Escalade 6.2L: a faulty MAP sensor. PIP5787A covers 2021 Escalades with the 6.2L L87 built between January 1 and February 15, 2021, with P00C7 ("Intake Air Pressure Measurement System Sensor and Multiple Sensors Correlation") and possibly P0106 and P0108. Here GM's stated cause is the sensor: replace the MAP sensor (part 12711681) and re-evaluate. A related service update, N212332660, had dealers replace the MAP sensor on 2021 Escalade and Escalade ESV models still in inventory because of an erratic MAP signal with P0106 and P0108. It applied to dealer inventory only and expired May 31, 2022, so for practical purposes it has passed — though a dealer VIN check is free.

2016 Escalade: the 5-volt reference. PIP5344 lists a check engine light and/or reduced power with any of P0106, P0107, P0697, P2122, P2123, P2127, P2128 and P2138 — codes that share a 5-volt reference circuit. If published diagnostics are inconclusive, GM says to inspect the wiring harness near the left instrument panel junction block, where it can be pinched on a mounting stud. See our 5-volt reference circuit guide.

Symptoms of P0106

• Check engine light — potentially on the first trip on a Northstar or a CT6 3.0TT
• Rough idle, hesitation or stalling (named in PIP5529B)
• Idle speed lower than desired, often logged as P0506
• Misfire and a ticking or tapping engine noise on a 6.2L with a broken valve spring
• Reduced engine power when a shared 5-volt reference is involved
• Sometimes no driveability change at all

Causes and How to Confirm Each

How Is P0106 Diagnosed?

1. Record every code and freeze frame. P0106 with P0171 suggests a leak; with P0506 or P0300 on a 6.2L, a valve spring; with other 5-volt reference codes, wiring.
2. Have the VIN checked for PIs and service updates — especially on a 2013–2017 ATS, CTS or CT6, a 2015–2019 Escalade or CTS-V, or a 2021 Escalade.
3. Compare MAP to barometric pressure with the key on and engine off after a rest. They should read about the same.
4. Watch MAP at idle and on a snap of the throttle. It should drop at idle and respond quickly and smoothly.
5. Smoke test the intake and, on 2.0T and 2.5L engines, check the intake manifold bolts.
6. On a 6.2L with P0506 or misfire codes, listen for valve train noise and plan a valve cover inspection.
7. Check the 5-volt reference and the sensor connector if other sensors on the same reference also have codes.
8. Replace the sensor only after the above, unless a PI for your build dates says otherwise, then clear and road test.

Parts and Cost

Order a MAP sensor by VIN. Turbocharged Cadillacs also have a separate boost pressure sensor, and the two are not interchangeable.

GM Documents That Name P0106 on Cadillacs

Have a dealer check your VIN against current bulletins and campaigns rather than relying on any article, including this one.

What Other P0106 Pages Get Wrong

• "P0106 means a bad MAP sensor." GM's Cadillac documents more often point at bolts, wiring or a valve spring. Only one 2021 PI names the sensor itself.
• "Replace the intake manifold gasket." GM's PIP5529B says retorque with threadlocker first.
• "It's harmless on a V8." With P0506 or misfire codes on a 6.2L Escalade or CTS-V, GM sends technicians looking for a broken valve spring.
• "Every Cadillac uses P0106." GM's tables for the Catera, the 3.2L CTS and the early 3.6L V6s do not list it.
• "MAP and boost sensors are the same." Turbo Cadillacs have both, and they are not interchangeable.

Frequently Asked Questions

Is P0106 serious?

Often it is a driveability and emissions issue. On a 6.2L Escalade or CTS-V with misfire codes, an idle code or engine noise, it can be the first sign of a broken valve spring, which should be inspected promptly.

Can I just replace the MAP sensor?

It is a common guess, but GM's Cadillac bulletins mostly fix other things. The exception is the January–February 2021 Escalade build covered by PIP5787A, where GM does replace the sensor. Check your VIN first.

Why does my Escalade show P0106 and P0506 together?

GM's PIP5423B links that pair on 2015–2019 Escalade and CTS-V 6.2L engines to a possible broken valve spring. The check is a valve cover inspection, plus an intake runner inspection if a spring is broken.

My CTS 3.6L never sets P0106. Why?

GM's tables for the early 3.6L V6s (LY7 and LLT) do not list P0106. Air problems on those engines usually show up as MAF or fuel trim codes instead.

Can a vacuum leak set P0106?

Yes. The modern test compares measured MAP to values calculated from the MAF and throttle, so a leak or loose manifold can push the reading away from the model.

Is there extended coverage for P0106?

We found none. The 2021 service update for the Escalade MAP sensor covered dealer inventory only and expired May 31, 2022. Valve spring repairs in PIP5752M reference powertrain coverage, which depends on your vehicle. A dealer can check your VIN.