Intermittent Engine Light/Dashboard Malfunction

[CAPwTDIs]

HELP -- sometimes while driving, the dahsboard needles on my '96 Passat will drop to zero (no degradation in performance of vehicle); if I tap the top of the dashboard, the needles return to normal position but check engine light comes on. Light may also come on about a minute after start-up although needles return to normal positions. Light eventually goes out by itself after a few hours, miles or days (no predictable pattern) and may not come on again for weeks (while driving). Seems to happen more in warm weather after several starts and stops. Light always goes out quickly at start-up, even in cold weather, although I wait extra time before turning key. Replaced the harness, control unit and relay last year which did not solve the problem. Still reading same codes. Any suggestions?

 

[thebigarniedog]

HELP -- sometimes while driving, the dahsboard needles on my '96 Passat will drop to zero (no degradation in performance of vehicle); if I tap the top of the dashboard, the needles return to normal position but check engine light comes on. Light may also come on about a minute after start-up although needles return to normal positions. Light eventually goes out by itself after a few hours, miles or days (no predictable pattern) and may not come on again for weeks (while driving). Seems to happen more in warm weather after several starts and stops. Light always goes out quickly at start-up, even in cold weather, although I wait extra time before turning key. Replaced the harness, control unit and relay last year which did not solve the problem. Still reading same codes. Any suggestions?

search "coolant migration" or your cluster is shot

 

[CAPwTDIs]

The 2 trouble codes detected were 00626 - Glo Plug Indicator Light K29 open circuit/short circuit to Ground sporadic; and 00750 - warning lamp open circuit/short circuit to Ground sporadic. Could these codes mean there is still something wrong with the glo plugs, harness, relay, fuse or control unit and if so, wouldn't the engine light stay on to reflect the problem?

 

[weedeater]

these codes would tell me it's a cluster problem.

 

[Franko6]

Before you go and trash a cluster, check the grounds. Lots of troubles relate back to ground faulted circuitry.

 

[thebigarniedog]

The 2 trouble codes detected were 00626 - Glo Plug Indicator Light K29 open circuit/short circuit to Ground sporadic; and 00750 - warning lamp open circuit/short circuit to Ground sporadic. Could these codes mean there is still something wrong with the glo plugs, harness, relay, fuse or control unit and if so, wouldn't the engine light stay on to reflect the problem?

Have you wired anything in the recent past? (i.e. radio, amp, etc?)

 

[TDIJetta99]

Figured I'd post here... She dropped the car off to me the other day... Here's what I found in the cluster this morning... I touched up about 12 solder joints and it works like new...